This TV had been repaired by other electronics repairer before it got to my shop. The reason I am saying this because, the moment I opened the cover to the TV set, I found the HOT was missing from the high voltage area and I could see that there was a lot of new fresh soldering areas all over the PCB board.
The first step to fixing this set is to install a light 100 watt light bulb in the place of the HOT in the high voltage section. I solder the one end of the light bulb to the collector and the second end to ground. I turned the TV on but the light bulb did not light indicating a power failure in the power section. I traced the problem backward starting from the b+ leg of the fly back transformer. There was nothing bad on the way which assured me of the problem in the power supply.
I started checking for bad component in the primary section of the power supply with an ESR meter and found a bad capacitor that has high ESR reading. It was in (C848) 100uf/63 volts. I checked all the parts in the power section primary and secondary sides and all checked fine. I powered up the set with the light bulb still attached and the light bulb came on and I tested the voltage there, it was 135 volts. With a TV size of (29”) the B+ voltage was considered normal.
Now, I had to find a replacement for the HOT in the high voltage area. I could not find the person who took the HOT out although I asked the customer but he had no idea. So I had to experiment with it. This is a big set and I thought it would be wise to use a HOT with a high amp rate. The only place I could find that was in a computer monitor. So I soldered the C4288A transistor as replacement. I fired up the set and it really worked. I hooked the set to my satellite receiver and it worked for more than two hours without problem.